1. Field of the Invention
The present invention relates to air circulation systems for generally enclosed structures such as homes having a floor and wall portion.
The present invention more particularly relates to an improved heat transfer and air circulation system for homes and like constructions wherein heat is removed from the home or like construction and stored for later utilization, with a non-conductive aggregate structural circulation medium supporting the home and transmitting circulating air from the home to the area adjacent the underlying soil mass.
2. General Background and Prior Art
In homes and other like constructions, fossil fuels or other energy is spent usually in the form of generated electricity for heating and cooling of the home. Thus, the average home requires energy which is ever shrinking and ever more expensive for its comfortable climate control.
Thus, there is a need for a more efficient system for heating and cooling the home which will allow it to more efficiently and less expensively be temperature controlled without the excessive use of electricity, fossil fuels or other consumed energy.
Most homes are of a slab type construction, meaning that the home sits on a probably four to six inch thick mass of concrete, which is poured on the ground (and some distance below in many cases) and provides a structural support for the home. Other secondary support such as piling can communicate with the slab to provide a structural base which will not sink under the load of the home and the slab itself.
In most climates, in the ground immediately under the slab there is a temperature fluctuation which often times is directly variable with the temperature of the atmosphere around the home yet coincident with the desired temperature in the home. For example, during the heat of the day the soil beneath the home is usually many degrees cooler. Further, in the winter the outside air is usually much cooler than the ground many inches or feet below the ground surface. Indeed, it is recognized that a "frost line" exists below which pipes and other matter will not freeze.
In a like manner, many inches or feet below the slab of the home cooler temperatures exist than in the atmosphere of the home in the mid day heat. Usually, the earth or soil at the frost line is constant temperature year round.
It would thus be desirable to circulate air through a medium provided below the home to the earth and return it to the inside of the home to either supplement the existing cooling system in the home or provide the total cooling system therefor. In winter, heating could be accomplished by circulating air taken from the home to the relatively constant temperature earth, and returning it to the interior of the home.
Many prior art type devices have been patented, which have attempted to solve the problem of air circulation and climate control within homes and similar inhabitable constructions. Many of these devices have provided a medium of some sort beneath the ground through which air can be circulated and heat transfer effected.
In U.S. Pat. No. 2,828,681 issued to Harry F. Smith, there is provided an "Air Conditioning Apparatus". The Smith device depends on an impervious strata and a porous strata. A shaft is provided which is sunk into the strata approximately three feet above the water level, which shaft is combined with an air pump for the purpose of drawing out air from the sub strata. Other shafts are placed about the outlet shaft for the purpose of allowing air to circulate inwardly. The concept of this patent is to draw air for the room or areas to be cooled within a home or similar construction, pump the air down through the strata to outlets where air is passed to the rooms or areas as cool air in the summer. The heat is absorbed by the strata and stored for winter heating.
In U.S. Pat. No. 2,167,878 issued to R. B. Crawford and entitled "Air Conditioning System", there is provided a device directed to the problem of obtaining refrigeration or heating from the earth or ground water. The Crawford device provides a conduit or channel which is lined with precast concrete blocks and has openings 11, which allow water to gravitate into the artificial channel. Flow lines circulate the fluid while a pump pumps the fluid therethrough.
In U.S. Pat. No. 2,559,870 issued to F. W. Gay, there is provided a "House Heating System" which utilizes a fan for circulating air through ducts which collect air beneath the basement of the house structure. Separate compartments are defined by I-beams with the I-beams being inter-connected so as to provide a single air space from side to side underneath the house.
Another patent issued to F. W. Gay is U.S. Pat. No. 2,584,573 entitled "Method and Means For House Heating". This latter Gay patent attempts to supply solar heat to a ground storage chamber thereby increasing the amount of stored heat available for heat pump operation in very cold winter weather.
A further patent issued to F. W. Gay is U.S. Pat. No. 2,780,415 entitled "Heat Pump Operating System For House Heating". A heat stored area is provided beneath the house in this patent which provides a number of trenches traversed by a perforated water pipe embedded in gravel with which each trench is filled.
In U.S. Pat. No. 2,793,509 issued to V. I. Keen and entitled "Method of an Apparatus For Cooling Inhabitable and Other Enclosures", there is provided a plurality of air conveying pipes which communicate with an artificial bed as a heat exchanger. The air is drawn through the conveying pipes to affect a heat exchanging.
A further patent directed to the problem of cooling structures by circulating beneath the building is provided in U.S. Pat. No. 2,829,504 issued to R. C. Schlichtig entitled "Air Conditioning System for Dwellings". An air well is constructed beneath a building unit through which air is flowed for heat exchanging.
In a recent U.S. Pat. No. 4,051,891 issued to Henry Harrison and entitled "Heat Transfer Block Means", a blower is provided which circulates air through a block structure that consists of a plurality of substantially equally sized stones. The stones are grouted or cemented together.
Other prior references dealing with this general subject matter have been cited and discussed in files of the copending applications referred to above.
Some prior art devices require complex structural support for the home or construction. Others do not have adequate detention time provided by their circulation medium for the circulated air to effect proper heat transfer.
In the heat transfer media provided or suggested by some prior art devices/systems, heat conductive material is used, allowing premature heat transfer before air currents reach the underlying earth creating "hot spots" in the circulation medium.
Some systems do not properly insulate the frost line area of the underlying soil to provide a "thermal cap" between the supported structure and the relatively constant temperature frost line area soil mass.
A heating/cooling of the floor area which contacts critical human extremities (as feet) is not achieved by prior art devices without supplemental conventional heating or cooling.